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Tulcea, Romania · 180 winters, 1836–2016

How many times has the Danube frozen in your lifetime?

At the river station in Tulcea, near the Danube's mouth, observers logged how many days each winter the river lay under ice: 180 winters in a row, up to 2016. Type your birth year, and your family's if you like, and the river replays every winter of your lives.

The years stay on your device.

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How a river closes

First comes a thin skin of ice along the banks. Then the floes: slabs of ice that drift downstream, collide and catch on each other.

When they stop and weld from bank to bank, the river is closed. Romanians call it a pod de gheață, an ice bridge: a continuous layer covering the whole river. At Tulcea, the number of days it lasted was logged every winter.

101 days

The longest winter in the record is 1879–80: the ice bridge held for 101 days, from December into March. This was Tulcea that winter, the river shut from bank to bank.

All 180 winters

Scroll: each winter passes from December to March with as many days of ice as were logged.

Winter 1836–37. The first line of the record: about three weeks of ice bridge.
1851–1854. Three winters in a row with no ice bridge. Even in the 19th century the river did not freeze every year.
Winter 1879–80. 101 days, the record.
So far: 92 winters with an ice bridge out of 114. Four in five.
Winter 1953–54. Three months of ice. The last three-month winter.
1960–1984. 24 winters in a row without an ice bridge, more than in the 114 winters before 1950 put together (22).
Winter 1984–85. 68 days. The last winter with more than two months of ice.
Winter 2011–12. About five weeks. The most recent ice bridge in the record.
Winter 2015–16. The published record ends here.

Your winters

By year of birth

How many ice-bridge winters at Tulcea someone born at the start of each decade lived through: in their first 12 years, and up to 2016.

Born inBy age 12By 2016
19001048
1910840
1920834
19301027
19401019
1950510
196005
197005
198025
199013
200022
20101 of 61

Before 1950, four winters in five. After, 10 in 66.

Until 1950, the ice bridge came in 92 winters out of 114. From 1950 to 2016, in 10 out of 66.

1850190019502000
Each bar is a winter, from 1836–37 to 2015–16. Its height is how many days the ice bridge held.

The change was not gradual. The record flips from one state to another within a few years around mid-century; the study's statistical tests place the break near 1943 for ice and 1947 for winter temperature.

The study ties the decline mainly to warmer winters. At Sulina, 70 km downstream, the December–February mean was around 0 °C in the 1880s. After 1960 it rose to 1–2 °C, above 2 °C in the 2000s, and in the winters of 2019–2026 it was 4.4 °C.

Same cold, different river

Winter 1887–88 and winter 2002–03 were equally cold at Sulina: a mean of −1.1 °C over December, January and February.

In winter 1887–88 the ice bridge held for 76 days. In winter 2002–03 it never formed.

The pair is not an outlier. From the start of measurements at Sulina (1877) to 1950, all 29 winters with a mean below zero brought an ice bridge to Tulcea. After 1950, only 4 of 8 did.

The study's authors found the same across the whole record: before 1950, a winter mean of −0.54 °C was enough to freeze the river; after 1950 it took −1.05 °C. They suggest water pollution, from waste water and heat discharged into the river, may be an extra factor; the idea has not been tested.

A winter mean is a rough measure: runs of hard frost matter, and so does ice drifting down from upstream. The station's adjusted series makes winter 1887–88 slightly warmer still (−0.86 °C), which widens the contrast.

After 2016

In January 2017, floes stopped the passenger boats on the Danube's branches and more than 11,000 people in the Delta's villages were cut off for days (Adevărul). That was drifting ice, not a logged ice bridge.

On 19 January 2026 floes appeared on the Old Danube; the main branches flowed normally (Agerpres).

A Delta captain, Costi Susac, remembered two months stuck in the ice near Chilia with his ship, until a huge slab came at them, rammed the hull and lifted the pontoon.

Ask while you can

A child born in Tulcea in 1940 saw the river close 10 times before turning 12. One born in 1960 saw it five times up to 2016, in 56 years. If someone in your family was born in those years, call them on the first hard frost this winter and ask what the Danube looked like when it froze. If your family's river is another one, ask about that: the Thames froze too, and its frost fairs are on this site.

Sources and method

Ice-bridge durations for each winter were measured by us from the chart in the study by Monica Ionita and colleagues (Scientific Reports, 2018), because the paper does not publish the table. Readings are good to about two days, and they match every count the paper states: 101 days in 1879–80, ten ice winters between 1951 and 2016, and 1984–85 as the last winter over 60 days. Freeze and thaw dates in the scene come from the same chart, to about three days, and are illustrative.

The paper credits the Danube Commission with starting the observations in 1836. The European Commission of the Danube was only founded in 1856, so the first two decades probably come from other sources the authors compiled.

Winter W runs from December of W to March of the following year. “By age 12” counts the first 12 winters starting with the birth year's. Sulina temperatures are December–February means from NOAA's GHCN-M v4, unadjusted except where the text says otherwise. The map of Tulcea is from OpenStreetMap.